Bow limb attachment systems are described by Kaneko in Japanese patent 52,19498 and by S. Rudolph in German patent DE 39 27 336 C2. The bow limb attachment taught by Kaneko has the disadvantage that the bow limb is supported in a slot with a spiral spring. This spiral spring is supposed to store the energy for the shooting of an arrow. As a result, the bow limb functions as a lever. There is an inherent disadvantage in the lever/spiral spring combination taught by Kaneko in that the system acts completely undamped at the time of release of the arrow which results in an unsteady release. Further, the material structure of the bow is subject to strain and vibration of attachments to the bow such as a bow sight.
The usual solution to dealing with undesired vibrations is to install a stabilizer on the bow which has vibration dampening characteristics or to mount the bow in a vibration damper. The disadvantage with stabilizers is that the vibration from the limbs are transmitted through the riser before entering, the stabilizer and start to be reduced.
The bow limb attachment system taught by Rudolf reduces the problems of the limb attachment system taught by Kaneko to a considerable extent. However, the structure taught by Rudolf has other serious disadvantages. The limb of the low attachment system disclosed by Rudolf is supported in a limb pocket provided in the riser in a linear way such that the limb can only move about one axis. This restriction of the movement of the limb relative to the riser about a single axis is a disadvantage because very few archers are capable of drawing the bow ninety degrees relative to the limb. As a result, there is a twisting of the limbs which naturally is the greatest at the nock ends.
Further, in the limb attachment arrangement taught by Rudolf, when the bow is shot and the limbs return to their resting positions, the tension is equalized rapidly, giving a shock which causes a sideward movement of the string. This sideward movement has an adverse effect on the arrow as it leaves the bow. To withstand this effect, the arrow has to be stiffer and heavier.
Still further, the limb attachment mechanism taught by Rudolf has the problem that the stack of plate springs which dampen the vibrations is subject to the negative influences of water and dust which can get into the stack of plate. The water can come from rain or splashing. When water gets into the stack of plate springs, there is a change in the sound which can disturb the archer. There are further problems resulting from water getting into the stack of plate springs, such as the water lubricates the stack of plate springs so that they act differently as compared to when they are dry. The water can also cool the stack of plate springs which can also change the vibration dampening effect. Further, over a period of time, the water can also corrode the individual springs in the stack. This corrosion changes the friction characteristics of the plate springs which, along with the other problems mentioned above, changes the force draw curve of the bow.